Single-board computer
A single-board computer, often Engl. Single Board Computer (SBC ) is a computer system in which all necessary for the operation of electronic components are combined on a single circuit board.
Single board computers are used in industry primarily in the measurement, control and regulation technology (MSR). You can replace hard-wired controllers advantageous because changes in the control processes can be realized in most cases by simply changing the program there in many areas. At the same time, they are much cheaper than programmable logic controllers ( PLC) and thus can be effectively used in areas where a large PLC would be oversized.
Single board computer as the KIM -1, the Microprofessor I and the Apple I were in the mid- 1970s, one of the precursors of the later Home and personal computer. They were often built by computer enthusiasts and hackers and used later their distribution fell sharply to home users. Constructive seen the most home computers of the 1980s such as the Sinclair ZX81, the Commodore 64 or Atari ST can be considered as single-board computer, but have not usually referred to as.
Since about 2012 single-board have again become more common found in the private sector, such as the Raspberry Pi sold 2 million copies (as of November 2013). They are used for example as an inexpensive Media Center, Home Server, as a school computer or as an experimental device with Linux or Android operating system.
Construction
A single-board consists of at least the actual processor, a clock generator, a reset logic, a read only memory (ROM ) for the program, and input and output modules. With this equipment can already perform simple sequential controls. For more complex tasks, more components are required, especially of RAM to store or execute subroutines interim results, and EEPROM and / or flash memory for variable parameters that must survive a power failure.
Very often single-board computer with monitor circuits (Brown Out Detection, Watchdog ) are provided which reset the computer in the event of an unexpected error in the program or in the power supply in a defined initial state.
Furthermore, single-board computer with analog - to-digital converters, counter modules, communication interfaces, and other special circuits can be adapted to the respective application.
History
Single board came in the late 1970s with the proliferation of microprocessors on the market. They first covered the need for low-cost development systems, but were also ensures designed from the outset to be used in production environments.
With the progressive development of the microcontroller, the combined addition to the actual processor core, more and more functions in a single chip, also extended the range of applications. Today the descendants of the single-board computer in washing machines, automatic transmissions, remote controls, heating controls and countless other everyday devices and industrial needs stuck. Here, the small computer designed both to ever greater performance, even with 16- bit and 32 -bit processors, and in the direction of tiny trivial systems with only a few simple functions ( BASIC Stamp ).
Variants
Many home computers, such as eg the C64 or ZX 81, from structural point of view also single-board computer with integrated video output, complemented by keyboard, more controls, connections for peripherals and usually some form of storage - but without these extensions, they are not useful be used.
6502 single-board computer
In the early computer development, this single board computers were very common. For example, the models Apple I, KIM -1 and AIM -65, all based on the 6502 microprocessor. A kit based on the 6502 CPU was introduced as junior computer in May 1980 from the Elektor -Verlag and developed with several thousand copies in Europe a popular DIY computer. The junior computer was developed at Elektor of Loys night man, who joined as a journalist for the magazine chip later.
SC / MP single board computer
An early -yourself computer was published by Elektor -Verlag in June 1977 (G 3078EX ) on the basis of the SC / MP (type I). Another kit was brought by the electronics manufacturer, and study material provider Christiani -Verlag Konstanz than SC / MP computer teaching in 1978 to the market.
Z80 single board computer
As one of the first available in Germany 1977, the single-board computer Nascom 1 was based on the Z80 CPU on the market. The first computers of the English manufacturer Sinclair Research, the Sinclair ZX80 and ZX81 and ZX Spectrum series, were also single-board computer. On the basis of Z80 -compatible CPUs, more single-board computer (known as SBC) were realized, among others, the NDR small computer from the year 1984 by Rolf- Dieter Klein, as well as the Euro -Z80 ( Elektor -Verlag) from the year 1989. too Z80 emuf ( single-board microcomputer for universal fixed temperature program application) has been a common Einplatinentyp in DIY. Since Zilog Z80 processor is still available today, new systems with clock speeds of 20 MHz are currently being developed again.
Today's single-board computer
Until the 1990s, 8 -bit single-board computer, such as Intel 8085, Intel MCS -51 microcontrollers and their successors, to measuring, control and regulating purposes (MSR ) is used. Today, single board computers are equipped with powerful microcontrollers and cover the different needs for household, industrial, automotive and military purposes as embedded system. The trend is to integrate more and more functions ( standard interfaces, A / D converters, etc.) of the Einplatinencomputers directly on the same chip as the CPU. This can be reduced with increasing functionality of the unit price of these computers.
The known current single board computers for end users include Arduino, BeagleBoard, Cubieboard, Ethernut, PandaBoard, Raspberry Pi, TinkerForge, ODROID and NanoPC. Such computers are used as a music streaming client, media center, thin client or server, as control board in a Quadrocopter, as a weather station, FM radio station or as a control unit for dedicated Bitcoin mining hardware.